This invention is concerned with can handling equipment and particularly is concerned with equipment for manufacturing cans. Typical can handling equipment used in the manufacture of cans is described in Beyer's U.S. Pat. No. 3,952,698. During the manufacture of cans, the can bodies have a lubricant applied to them to assist in the shaping processes and in the other body formation steps. Thereafter, the formed bodies are delivered to a washing and coating equipment such as, for example, that described in the aforementioned Beyer patent.
It is conventional to coat both the interior and exterior surfaces of the can bodies. The interior surface is coated so that the contents of the can are prevented from reacting with the material of the can and the exterior of the can is commonly coated to provide a surface receptive to printing inks so that promotional and other information can be printed on the exterior surface of the cans.
After the can bodies are coated they are filled and a closure is then applied to the open end of the can bodies and the edges of the open end of the can bodies are necked and flanged to close the container. The washing and coating operations are performed with the can bodies in an inverted position, i.e. with the open ends lowermost. This particular orientation is used for the obvious reason that in the coating and washing operations, were the open end of the can uppermost, the interior of the cans would become filled with the washing and coating materials.
As a result of this particular orientation of the cans, in the coating stages a bead of excess material tends to form around the lowermost edges of the cans as the coating material, under the influence of gravity, moves down the surfaces of the cans. This bead of material can interfere with the flanging and necking operations and can be unsightly. The present invention is concerned with avoiding the formation of such beads upon can bodies.
The most pertinent art of which applicant is aware is that consituted by U.S. Pat. No. 4,009,050 (Beyer et al). In that structure, cans carried upon an upper course of a conveyor upon which coating occurs are passed to a conveyor constituted by a plurality of driven rollers which together define a course for the cans through a bath of solvent so that the lowermost edges of the cans dip below the surface of the solvent so that the bead of excess coating material be removed. Thereafter, the course moves upwardly from the bath and the cans are delivered from the end of the roller conveyor to a conveyor upon which the coatings are cured or dried.
Other pertinent prior art is represented by U.S. Pat. No. 4,020,198 issued Apr. 26, 1977 to Cornelius et al. That patent shows an overhead transfer conveyor for transferring cans from a belt conveyor upon which the cans are coated to another belt conveyor upon which they are dried. In between the coating and the drying conveyors there is a bath of a solvent and the overhead conveyor dips downwardly towards the bath to bring the lowermost edges of the cans carried by that transfer conveyor into contact with the solvent within the bath in this way to remove the bead of excess coating material.
The present invention seeks to provide an improved system for removal of the bead of excess coating material which forms on the lowermost edges of cans. Particularly, it seeks to provide a system which is effective not only for use with relatively narrow conveying belt systems but also is useful for a wide conveyor.